Your main issue sounds to be nose up throwing. Early slips are problematic for sure and tackier materials like FLX and medium Vibram rubber based discs for their first year help. They dry with age to as grippy as premium plastics from other companies. Some discs have grip enhancing shapes. Is Ching making the only drivers that have grooves/ridges? If you make a fist except leaving a tenth of an inch or so of an air canal in the middle and get the finger tips lining that canal and breath into the canal the skin is at body temperature in no time. You could spit or use a moist towel to further moisten the fingers and by rubbing the fingers together dissipating the excess you can have a tackier feel than with dry skin. Or you could catch dirt with the excess moisture and have sand paper like skin that can damage the disc. But the grip is awesome
Nose up is the first issue for most players after pulling the arm straight is learned. There are several reasons for that. One is reaching back lower than the release point. Another is having the weight back=you lean away from the target so an arm pull that would be level if you were upright rises. The wrist may be in neutral position which means that with a lifeline grip the front of the disc higher than the rear. The wrist needs to be pushed down at the rip so that the disc is at least level with the ground. It is fine to raise the rear of the disc up to the innermost seam of the thumb.
Thin and short winged discs allow for a greater leverage of the fingers in the grip for a stronger grip. You may be able to throw as far with just shy of widest winged discs if they have great glide. Like Prodigy D3 or D4, Westside VIP King but most of them are flippy and tall high outer edge having ones are not. Gateway Slayer is fine from hearsay and one throw, Bolt is flippy for a 400' thrower but perhaps ok with less distance.
Flat shots need running on the center line of the tee and planting each step on the center line. Anhyzer needs running from rear right to front left with the plant step hitting the ground to the left of the line you're running on. Hyzer is the mirror of that.